Nuclear Radiation

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Nuclear Radiation Transformations
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Marie Curie

• Marie Curie was a Polish scientist whose research
  led to many discoveries about radiation and
  radioactive elements. In 1934 she died from
  leukemia caused by her long-term exposure to
  radiation.

3
Radioactivity

• Marie Curie (1867-1934) and Pierre Curie
  (1859-1906) were able to show that rays emitted
  by uranium atoms caused fogging in photographic
  plates.
• Marie Curie named the process by which materials
  give off such rays radioactivity.
• The penetrating rays and particles emitted by a
  radioactive source are called radiation.

4
Radioactivity

• In nuclear reactions, the nuclei of unstable
  isotopes, called radioisotopes, gain stability by
  undergoing changes.
• An unstable nucleus releases energy by emitting
  radiation during the process of radioactive
  decay.

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Types of Radiation

• Alpha
• Beta
• Gamma

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Alpha Radiation

• Nuclear Symbol
• Made of
• Mass
• Charge

4
4
He
a
or
2
2
2 p and 2 n0
4
2
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Alpha Decay
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Beta Radiation

• An electron resulting from the breaking apart of
  a neutron in an atom is called a beta particle.

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Beta Radiation

• Nuclear Symbol
• Made of
• Mass
• Charge

0
e
0
or
ß
-1
-1
electrons (-)
0
-1
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Beta Decay
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Gamma Radiation

• Nuclear Symbol
• Made of
• Mass
• Charge

?
electromagnetic waves

• Usually emitted along with alpha radiation or
  beta radiation.

0
0
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Gamma-Ray Radiation
Cobalt-60
Nickel-60
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What stops alpha, beta, and gamma radiation?

• Alpha particles are the least penetrating. Gamma
  rays are the most penetrating.

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Nuclear Stability and Decay

• The stability of the nucleus determines the type
  of decay (alpha, beta, gamma) a radioisotope
  undergoes.
• The protons in a nucleus want to repel against
  each other.
• There is a strong force that holds the protons
  and neutrons together in the nucleus

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What makes an atom radioactive?

• When the strong nuclear force cannot hold the
  protons and neutrons together.

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Which elements are unstable (radioactive)?

• All nuclei with more than 83 protons (shade these
  in on the small periodic table)
• However, many other nuclei with only a few
  protons are also radioactive

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Transmutation Reactions

• The conversion of an atom of one element to an
  atom of another element is called transmutation.
• Transmutation can occur by radioactive decay.
• Transmutation can also occur when particles
  bombard the nucleus of an atom.

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Fission Fusion

• BOTH release A LOT of energy

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Fission

• A large nucleus is split apart.
• Usually releases particles that perpetuate a
  chain reaction

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Fission
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Fission

• A large nucleus is split apart.
• Usually releases particles that perpetuate a
  chain reaction
• Used to generate electricity and in nuclear
  weapons

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Fusion

• 2 small nuclei combine (fuse together)
• Occurs at very high temperature and pressure
• Occurs in the sun other stars

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Fusion
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Geiger Counter

• Used to detect radioactive substances

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Effects of Radiation
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Half-Life

• HALF-LIFE is the time that it takes for 1/2 a
  sample to decay.
• The rate of a nuclear transformation depends only
  on the reactant concentration.

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Half-Life
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Half-Life
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Half-Life

• The ratio of Carbon-14 to stable carbon in the
  remains of an organism changes in a predictable
  way that enables the archaeologist to obtain an
  estimate of its age.
• Radiocarbon dating is used to determine the
  approximate age of a sample of matter.